Overview

Hypersensitivity vasculitis is inflammation of the vessel wall which is usually due to a hypersensitivity reaction to a known drug, auto-antigens or infectious agents such as bacteria.

Pathophysiology

Immune complexes lodge in the vessel wall, attracting polymorphonuclear leukocytes who in turn release tissue-degrading substances leading to an inflammatory process. This disorder may affect the skin only, but sometimes affect nerves, the kidneys, joints and the heart. Renal involvement is common.

Treatment

The most important part of the treatment is to eliminate the cause of the vasculitis, if at all possible. Antihistamines prove helpful to some patients. If the vasculitis is damaging organ systems such as the kidneys, immunosuppressive agents are indicated.